Effect of Particle Size and Concentration of Nanocellulose on Thermal Properties of Nanocellulose Aerogel

Abstract Traditional building thermal insulation materials are mostly from petrochemical materials or high energy consumption processing process, which seriously restricts the sustainable development of the economy. Therefore, it is urgent to develop high-performance green insulation materials with high efficiency, energy saving, light weight and environmental protection. In this paper, nanocellulose aerogels made from cellulose nanocrystal (CNC) and cellulose nanofibril (CNF) with different concentrations were prepared by freeze-drying process. The effect of the concentration of nanocellulose on the thermal properties of aerogel was fully studied by infrared thermal imager, thermogravimetric analyser, and thermal conductivity meter. The study found that the overall thermal insulation performance of CNF aerogel was better than that of CNC aerogel. The concentration had a significant effect on the thermal insulation performance and thermal conductivity of the two aerogels. Among all the prepared nanocellulose aerogels, CNF aerogel with a concentration of 1% showed the best thermal insulation performance, which had a temperature difference of 24.1°C and a thermal conductivity of 0.030 W/mK.